Embodiments of the present invention use members of nature, structure and configuration achievable generally and/or specifically by implementing teachings of our parent application Ser. No. 08/707,012. Such members thus have capability to sustain and propagate input vibrational energy by bending waves in operative area(s) extending transversely of thickness often but not necessarily to edges of the member(s); are configured with or without anisotropy of bending stiffness to have resonant mode vibration components distributed over said area(s) beneficially for acoustic coupling with ambient air; and have predetermined preferential locations or sites within said area for exciter means, particularly operationally active or moving part(s) thereof effective in relation to acoustic vibrational activity in said area(s) and signals, usually electrical, corresponding to acoustic content of such vibrational activity.
Members as above are herein called distributed mode acoustic radiators and are intended to be characterised as in the above parent application Ser. No. 08/707,012 and/or otherwise as specifically provided herein.
This invention is particularly concerned with acoustic devices in the form of resonant acoustic radiator loudspeakers for use in passenger vehicles such as automobiles, aircraft, boats, railway trains etc, and to vehicles incorporating such loudspeakers.